Retirement and Deferred Compensation Plans - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) insurance_contract	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Retirement Benefits [Abstract]
Non-service component net cost (credit)	$ 2.8	$ 1.0	$ (5.3)
Pension plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation for plans that have plan assets	390.4	433.0
Accumulated benefit obligation for plans that do not have plan assets	86.0	86.7
Estimated net loss that will be amortized from AOCI into net periodic benefit cost during next fiscal year	1.2
Estimated prior service cost (credit) that will be amortized from AOCI into net periodic benefit cost during next fiscal year	0.7
Estimated employer contribution to pension plans during next fiscal year	7.8
Pension plans | Germany
Defined Benefit Plan Disclosure [Line Items]
Unfunded portion of plan	(56.4)	(61.8)
Pension plans | Non-United States Plans
Defined Benefit Plan Disclosure [Line Items]
Unfunded portion of plan	$ 95.9	$ 112.8
Expected long-term return on plan assets	2.70%	2.80%	3.40%
Number of foreign plans using guaranteed insurance contracts | insurance_contract	4
Net loss recognized in accumulated other comprehensive loss	$ 16.5	$ 29.9
Prior service cost (credit) recognized in accumulated other comprehensive loss	$ 7.7	$ 6.7
Discount rate used in measurement of benefit obligation (as a percent)	2.40%	2.10%
Pension plans | Non-United States Plans | Minimum
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets	1.50%
Pension plans | Non-United States Plans | Maximum
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets	3.50%
Retiree health care plan
Defined Benefit Plan Disclosure [Line Items]
Unfunded portion of plan	$ 13.7	$ 14.9
Estimated prior service cost (credit) that will be amortized from AOCI into net periodic benefit cost during next fiscal year	0.8
Net loss recognized in accumulated other comprehensive loss	0.9	1.4
Prior service cost (credit) recognized in accumulated other comprehensive loss	$ (4.1)	$ (4.8)
Discount rate used in measurement of benefit obligation (as a percent)	4.20%	3.50%
Discount rate used in measurement of net periodic benefit cost (as a percent)	3.20%	4.00%	4.30%
Health care cost trend rate assumed for next fiscal year (as a percent)	7.30%
Ultimate health care cost trend rate (as a percent)	4.50%